TY - JOUR ID - 15054 TI - On the effect of HPT processing conditions on relative density, mechanical properties and microstructural evolution of hot compacted AA6061– mathematical empirical and response surface approach JO - Advanced Materials Letters JA - AML LA - en SN - 0976-3961 AU - H. El-Garaihy, Waleed AU - M. Alaskari, Ayman AU - A. Ameshaiei, Eisa AU - E. Oraby, Samy AD - Y1 - 2017 PY - 2017 VL - 8 IS - 5 SP - 620 EP - 628 KW - AA6061 KW - high pressure torsion KW - ultrafine grained materials KW - nonlinear regression procedures KW - response surface methodology DO - 10.5185/amlett.2017.1402 N2 - A loading combination of hot compaction (HC) together with high-pressure torsion (HTP) was used to consolidate discs of AA6061 considering rotations up to 4 revolutions and loading pressure values of 1 and 3 GPa. Mathematical models were established to grasp the true functional interrelationships and variations in the resulting relative densities, mechanical properties, and micro-structural evolutions as affected by the HPT processing pressure and the imposed strain. Sequential iterative nonlinear regression procedures were employed to get the most suitable mathematical relationships that express the relationship between the variables under study.  The developed models were examined for its adequacy and significance by using ANOVA analysis as well as many other statistical criteria. Response surface and contour graphs were established for a better understanding of the true functional dependence and, for a quantitative assessment of the intended relationships. It was observed that uniformity of hardness distribution increased with increasing each of the equivalent strain (εef) and the imposed pressure. A remarkable increase in the compressive strength of deformed discs has been observed. HPT processing produced a tri-model structure with micron scale grains and subgrains, and nano-scale substructure.  UR - https://aml.iaamonline.org/article_15054.html L1 - https://aml.iaamonline.org/article_15054_1be199090deb0d25482d4b78551c3b5b.pdf ER -